Zion National Park in Utah is closing access to 13 popular rock-climbing cliffs as part of an annual effort to protect sensitive nesting sites for peregrine falcons.
The National Park Service announced this week that climbing routes will close March 1 to let wildlife biologists monitor nesting activity of the formerly endangered raptors.
Affected routes include Angels Landing, Cable Mountain, North Twin Brother, Mountain of the Sun and Tunnel Wall.
Officials plan to reopen sites that don't have nests by late April or early May.
Nest sites will be monitored until the chicks leave, typically in late July.
Zion is a sanctuary for the American peregrine falcon, a predatory bird that neared extinction in the 1970s but was removed from the endangered species list in 1999, after 20 years of recovery efforts.